On Wed, Jan 28, 2004 at 12:42:18PM +1100, Neil Brown wrote: > > On Tuesday January 27, atossava@cc.helsinki.fi wrote: > > Sorry about the crossposting. > > > > I wrote on the Yellow Dog Linux list when somebody asked about software > > RAID on YDL about my experiences with it: > > > > >> The one really big gotcha is that the Macintosh partitioning scheme > > >> can't tell the Linux kernel that certain partitions are to be > > >> considered "Linux RAID autodetect" (as in x86 using the DOS partition > > >> table type 0xfd). This means that you can't boot a Mac Linux system > > >> directly from RAID because the kernel won't be able to autostart the > > >> RAID devices. You have to work around this by creating an initial RAM > > >> disk that uses the raidstart command to start your metadevices, then > > >> swaps the initrd out of the way and proceeds to start the real system. > > > > This is not entirely true. Certainly an initial-ram-disk is one > solution and is (I think) the preferred long-term solution. However > you can also boot from raid with kernel-parameters like: > > md=0,/dev/hda1,/dev/hdc1 boot=/dev/md0 > > where '0' indicated which md device (md0 in this case), and the > remaining words are the devices to assemble it from. This is said to be broken on latest 2.4.x kernels though. Didn't try myself though, since i only have a single drive, and don't really want to mess up with it. > > to which Tim Seufert replied on the same list: > > > > > Hmmm. That would seem to be a lack in the Linux RAID code, since the > > > Macintosh partition table has a vastly more flexible partition type > > > field than DOS: instead of a single byte it's a string. It would mean > > > breaking from the convention of using the "Apple_SVR2_UNIX" type for > > > Linux partitions, but that really is just a convention as far as I know. > > > > Perhaps the PPC Linux developers and the Linux RAID developers should > > get together on this and make some decisions so as to make it happen. > > > > I personally think auto-detect is the wrong approach and have no > desire to extend it to other partition types (I cannot remove it from > DOS partitions as that breaks back-compatability). > Just use "md=..." Ok. Friendly, Sven Luther - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
